eVolo Magazine has an annual competition of skyscraper design. They call for "innovative designs that take into consideration the historical and social context, the existing urban fabric, the human scale and the environment."
So of course they are huge towers that do almost none of the above but are fascinating exercises nonetheless.
Second Prize winners Nicola and Adelaide Marchi present a 400 meter high bridge over the Seine River in Paris. More
Third prize winner Eric Vergne proposed "a dystopian stage of agricultural production which uses mans control over the growth process", towering over the Manhattan Navy Yards site. More here
In fact, this year vertical farms are all the rage.
Park Ju Sin and Lee Min Cheol propose a Manhattan Farming Residence;
Stephan Shaw and John Dent propose a Bio City;
Fabrice Henninger and Alexander Dabringhausen propose "A fertile impulse for Modern Metropolises."
Interesting stuff; Apparently New Yorkers will never go hungry as long as the elevators work. More at Evolo
Other Evolo winners in TreeHugger:
Other Interesting Entries in the Evolo Competition
Evolo Skyscraper Competition Results
and my very favourite one from last year:
Retrofitting our Skyscrapers For Food and Power